Computer-generated environments for human interaction are becoming ever more complex and realistic. These environments have moved beyond presenting limited environmental details on a fixed two-dimensional surfaces, such as a computer monitor or television screen, to head-mounted displays that can present a user with an immersive, completely computer-rendered experience, sometimes referred to as “virtual reality,” or selectively overlaying computer-generated images on analog-world image viewable by a user through visors capable of transparently allowing ambient light to reach the user's eyes, sometimes referred to as “augmented reality.”
Virtual and augmented reality systems (collectively referred to as computer-generated environments) can allow a user to interact with a fully or partially simulated environment in a variety of manners that typically are more engaging and complex than traditional interactions, such as video games. For example, a user may be allowed to freely move and look about an environment, rather than being constrained by software-imposed environmental limitations, such as only having certain a certain horizontal or vertical range of an environment available for a user to view. Virtual and augmented reality systems typically relax or remove these kinds of restrictions.
The sense of immersion can be greatly enhanced by display visors occupying a user's entire field of vision, such that the user is never removed from the computer-generated or enhanced environment. For traditional fixed, two-dimensional displays, if the user turns their head, or the viewing device occupies a sufficiently small portion of their field of vision, the user can be interrupted from their experience. In contrast, with typical virtual and augmented reality display devices, the computer-generated environment can be maintained no matter where the viewer chooses to direct their gaze.
Advances in hardware and software have reached a stage where the visual and audio experience provided by virtual and augmented reality systems can be very convincing. While high-end gaming consoles and dedicated virtual/augmented reality systems can present exceedingly realistic visual and audio content to a user, even comparatively simple devices, such as smartphones, can be adapted to present surprisingly immersive environments to a user, such as by inserting a smartphone into a specialized holder that places the device screen in sufficient proximity to a user that it occupies a substantial portion of the user's field of vision. However, devices that allow a user to interact with computer-generated environments, including receiving tactile/haptic feedback, have not reached the same level of refinement as the audio and visual content.
User interaction with a computer-generated environment can be of several types. One type of interaction modality can involve the user traversing a computer-generated environment. For example, in a simulated analog world situation, how are changes in the positions of the user's body, such as the position of the user's head (such as to determine where the user is looking, and thus what should be visually or audibly rendered) determined and translated into corresponding, realistic environmental changes in the simulated environment? If a user wishes to move within an environment, how can this input be provided?
Haptic interaction is another type of user interaction that is typically of interest in virtual and augmented reality environments. For example, if a user touches a rendered object, the system should be able to detect the interaction, and provide realistic audio, visual, and haptic feedback to the user. In hitting a baseball in the real word, for instance, the user would see the ball hit the bat, see the trajectory of the ball altered as a result, hear the interaction of the bat with the ball, and receive haptic feedback for a variety of sensations, including the physical presence of the bat in the user's hand, the texture of the bat, and the impact of the bat with the ball. The more of these sensations that can be realistically conveyed to the user in a computer-generated environment, the more realistic and immersive it will be. Correspondingly, each element of a computer-generated environment that does not match with a user's expectation of a corresponding analog-world situation can disrupt the immersivity of the computer-generated environment.
To date, haptic devices typically suffer from a number of disadvantages, including providing a specific, limited type of haptic feedback, being expensive to build, providing obvious but unnatural behavior, and being cumbersome for the user to out on and take off. Proposed hand-held or hand-worn haptic devices include exoskeleton hand gloves for grasping, fingertip devices for rendering shear force and weight, vibrotactile devices for rendering textures, controller type devices for touching, and exoskeleton haptic suits for kinesthetic feedback to the entire arms. Devices such as exoskeleton gloves or suits, in addition to their complexity and expense, can be cumbersome for a user to put on and take off. For example, even getting a first glove on can be difficult, getting a second glove on can be even more frustrating for users, since they do not have an ungloved hand to use. Difficulty in putting on and taking off devices can be particularly problematic if a user needs to rapidly switch to a different modality in the computer-generated environment, or to deal with a situation in the analog world (e.g., answer the door or a phone call). Accordingly, room for improvement exists in the design of haptic devices for use in virtual and augmented reality scenarios.